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ABOUT US – Enabling The Future
Learn a little about the grassroots, open-source e-NABLE Community and our history!
The e-NABLE Community is an amazing group of individuals from all over the world who are using their 3D printers to create free 3D printed hands and arms for those in need of an upper limb assistive device.
They are people who have put aside their political, religious, cultural and personal differences – to come together and collaborate on ways to help improve the open-source 3D printable designs for hands and arms for those who were born missing fingers or who have lost them due to war, disease or natural disaster.
The e-NABLE Community is made up of teachers, students, engineers, scientists, medical professionals, tinkerers, designers, parents, children, scout troops, artists, philanthropists, dreamers, coders, makers and every day people who just want to make a difference and help to “Give The World A Helping Hand.”
April 2011 | It All Began with Cosplay Nerds!
In April of 2011, artist and designer Ivan Owen created a crazy metal functional puppet hand to wear to his first-ever steampunk convention with his fellow artist and friend, Jen Owen.
Ivan’s giant metal hand was a huge hit at the event and when they returned home from their adventure, he decided to post a short video of it on Youtube.
December 2011 | The Email
The video that Ivan shared was somewhat forgotten about until one evening, he opened his email to see a message from Richard, a carpenter in South Africa who had lost his fingers in a woodworking accident. Richard asked Ivan if he would be interested in helping him to create a functional finger replacement after he had searched online and discovered that a single prosthetic finger would cost him around $10,000 US Dollars.
He had been trying to design his own, but came upon the video that Ivan had uploaded and reached out for help.
January – October 2012 | Collaboration Across 10,000 Miles
Because Ivan and Richard were 10,000 miles apart, they had to work together through skype and email.
In early January of 2012, Richard sent a plastic mold of his hand to Ivan so that Ivan could design a device specifically for him.
Ivan started researching prosthetic devices and stumbled upon the story of Corporal Coles hand. It was created in the early 1800’s by an Australian dentist named Dr. Robert Norman who constructed it from whalebone, cables, and pulleys. This one hand, created over 100 years prior, inspired the design of what is now the building block for every e-NABLE Community 3D printed hand.
During the design process, they had to use objects they could both find around their homes and respective countries. Sometimes this involved items such as toilet paper tubes, leather scraps, zip ties, fishing line, rubber bands, surgical tubing, duct tape and various other items they could find.
March 2012 – First Blog is Created
As Ivan and Richard started making progress on the design for a single finger, Jen had started photographing the stages of development and sharing with her family and friends on social media channels.
She decided it would be easier and more fun to create a blog, so that those that were interested in following their story, could visit and read about their adventures.
The Media started picking up their stories.
November 2012 – Time to Meet in Person
In early September, Ivan and Richard realized they had gone just about as far as they could go through online communication. They started a crowdfunding campaign to help get Ivan to South Africa so that he and Richard could work in person.
While they were raising money for airfare, a generous donor provided frequent flier miles so that Ivan could get to South Africa.
November 2012 – Along Came Liam
As more news articles and social media clips started circulating about Ivan and Richard’s work on a single finger design, people started reaching out to them personally to ask for help.
One of those people was Yolandi, the mother of a 5-year-old boy named Liam. Their family also lived in South Africa and she had read that Ivan was planning to fly down there to help Richard and had hoped he would be able to help her son too.
Liam was born missing his fingers on his right hand due to Amniotic Band Syndrome. He had never had fingers on his right hand before, so he had learned to do everything without them.
She had read the blog and had seen stories on Facebook. She messaged to ask if Ivan and Richard would be interested in creating a whole hand for her son, instead of just the single finger.
November 2012 | The First Prototype for an e-NABLE Hand Came to Life.
Yolandi had reached out just in time.
With just 3 days before he was set to leave on his journey, Ivan was able to take the design for that giant mechanical hand he had created for that first Steampunk convention, and shrink it down to a tiny 4 fingered version that he would be able to take with him to South Africa.
November 2012 | The World Was Waiting
After Ivan boarded his flight to head off on his long journey to meet Richard in South Africa, Jen asked people to send her videos and photos of themselves with words of encouragement for them.
Friends, family and even strangers showered them with images of inspirational quotes written on their hands, holding up posters and sending love to them from afar.
Thanksgiving 2012 | Liam’s New Hand
With a limited number of days available to work in person once he landed in South Africa 28 hours after leaving the USA, Ivan and Richard jumped right into finalizing the single finger prototype for Richard.
They then invited Liam’s family over for a full day of building what would ultimately become the original e-NABLE hand.
Liam was able to help build his very own hand.
It was made from aluminum bar stock, rivets, screws, copper tubing, fishing line and some thermoplastic. While it was bulky, awkward and still missing a thumb, Liam was able to strap it to his arm and pick up a ball and other objects for the first time in his life.
December 2012 | Liam’s Progress
Little Liam practiced daily with his new hand with the help of his mom and brother.
She created exercises for him to do at home and sent videos to Ivan to share.
Liam was determined to make his new hand work and learn how to use it, instead of getting frustrated and giving up. Because of this, Ivan and Richard were able to see how he was using the hand to get ideas for improvements for the next design.
December 2012 | The First 3D Printed Prosthetic Hand for a Child
While creating that first hand prototype for Liam, Ivan and Richard realized that because of his age, Liam would quickly outgrow the device and it would be exhausting trying to keep remaking it out of the same materials.
Ivan started researching the use of 3D printing to create the next version.
He taught himself how to use 3D printer design software and contacted Makerbot, a 3D printer company to ask if they would be interested in donating a 3D printer so that he could make new hands for Liam as he grew.
Makerbot was excited to see what they were doing and donated 2 3D printers so that Ivan could design and send the files to Richard via email, who would then in turn print them out on his machine and assemble into a hand for Liam to test out.
They called the first device a “Robohand.”
Liam would then give them feedback on what was working and what didn’t feel good in each new design until they came up with the final prototype for him.
January 2013 | The first 3D Printed Open-Source Design is Shared with the World
After watching Liam with his new 3D printed hand they all realized that if this design could help one child, it could potentially help thousands.
They made the collective decision to forego any potential to make profits from this design and instead, published it to the internet as an open-source, public domain file so that anyone, anywhere in the world with access to a 3D printer – could make one for themselves or someone else in need.
The best chance for the design to help the most people, was to share it and hope those other designers would find it and improve it and reshare it back into the world.
July 2013 | The e-NABLE Google Plus Community is Born
In exchange for the donating two 3D printers, Makerbot asked that they get to create a video to share about the first 3D printed hand prosthesis for Liam.
Once the video was shared, fellow makers and 3D printing enthusiasts started leaving comments on the video to state that they would be interested in helping to make 3D printed hands for other people who may need them too.
Jon Schull, then a professor at RIT, noticed that people were interested in helping and decided to start a Google Plus community where they could gather and communicate.
He set up a Google Map where those who had 3D printers and wanted to help, could put a pin to show their location and let those who needed a 3D printed hand know how to find them.
He left a comment on the video and invited people to join.
By the end of July, the first 70 e-NABLE Volunteers had joined the Google plus community and were actively working on cleaning up the designs and trying to locate recipients.
January 2014 | The enablingthefuture.org Website is Created
Jen suggested that this new community allow her to start sharing their stories and create a blog. With their permission and the permission of the recipient families, she created enablingthefuture.org – the home of the e-NABLE Community’s history and stories of inspiration and hope.
The media started picking up the stories and families with limb different children started finding the e-NABLE Community and asking for help.
January – September 2014 – e-NABLE Superheroes
Famlies starting finding the Google Plus Community and volunteers began creating devices for recipients and connecting with these families.
Parents of limb different children were joining and becoming designers and makers of these hands themselves.
Designers started getting creative with and the recipients were eager to get their own “Super Hero” hands.
Many of the children who have upper limb differences, tend to be bullied or feel very self-conscious and tend to hide their hands and arms.
Now, with superhero themed hands, they were suddenly the envy of everyone in the class.
Volunteers started teaching families and recipients how to assemble their own devices. Children were building their own 3D printed hands and learning how to teach others to do the same.
September 2014 | e-NABLE’s First Conference
In September of 2014, Dr. Albert Chi, a leading trauma surgeon learned about e-NABLE and invited the community to hold a conference at Johns Hopkins Medical Center.
They called it “Prosthetists Meets Printers.”
Over 400 people attended. The participants were made up of medical professionals, hand therapists, medical students, e-NABLE volunteers and 25 recipients and their families.
In just 72 hours, the global e-NABLE Community had been given a call to action to send as many 3D printed hand parts as possible to the conference so that volunteers could teach not only medical professionals how to assemble the devices, but also the families and recipients.
December 2014 | The First Hand-A-Thon is Born
After attending the e-NABLE Conference and joining the e-NABLE Community, volunteer Maria Esquela put together an event with local scout troops in Baltimore. She created the first-ever e-NABLE “Hand-a-thon” where over 100 boy and girl scouts, their parents and mentors spent their entire Saturday, working in teams to assemble 3D printed hands.
The hands were boxed up and sent to a clinic on the Syrian border where children and adults who had lost their hands due to war, were waiting for them.
January 2014-December 2015 | Design Boom
Throughout 2014, the e-NABLE Community exploded with new designs. Designers were joining by the thousands.
By the end of 2015, the first 3D printed, low cost, myo-electric version had been developed.
Teachers starting using e-NABLE as an example of how 3D printing could be used as STEM based learning projects in their classrooms. Thousands of students all over the world started participating in the project.
e-NABLE Today
The e-NABLE Google Plus Community started with around 100 people who were simply offering to print the files that were already in existence. A handful of devices had been made for children in various parts of the world.
Within that first year – the e-NABLE community grew from 100 members to over 3000. They created over 750 hands for people around the world and numerous new designs had been developed. The designers reshared those files into the public domain as open-source designs.
Within another year – they had more than doubled to nearly 7000 members with approximately 2000 devices created and gifted to individuals in over 45 countries.
All of these 3D printed hands and arms were free to the end user thanks to the incredible volunteers in our community.
By the end of 2018, the e-NABLE Community had over 10,000 members.
As of November 2019, nearly 7 years after the first device was created for Liam out of metal and scrap materials, there have been approximately 7,000 3D printed hands and arms created and gifted to children and adults in need in over 100 countries around the world. There are an estimated 30,000 e-NABLE Volunteers (Including students and teachers) who are helping to make a difference in their local communities, clinics and schools all across the globe.
There are over a dozen new designs and more being shared every day.
The e-NABLE Community has over 140 e-NABLE Chapters and hundreds of schools participating in helping to make free 3D printed hands for those in need.
You never know where your ideas and imagination will take you!
Will you join us?
Together, we can change the world.
“Now all the fingers of this tree (darling) have hands, and all the hands have people; and more each particular person is (my love) alive than every world can understand…” – E.E. Cummings
Liam with one of his 3D printed e-NABLE hands.
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3D Printing For Good: How One Nonprofit Is “Printing” Homes For Families In Need
Alexandria Lafci was 24 years old and stuck in a job she hated when she decided to pursue an unlikely dream: Building homes for families in need around the globe. She had learned so much in her first job out of college and now she wanted to apply that experience: The Teach for America alumna had seen firsthand how homelessness affects a child’s mental, emotional, and physical well-being: Nearly one-third of the students she taught in Washington, D.C. experienced homelessness at some point during the school year.
So together with her co-founders, Alexandria launched New Story, a nonprofit that is transforming slums into sustainable communities by harnessing the power of 3D-printing technology.
In 24 hours, their organization can “print” a new, 600-square-foot home for under $4,000. So far, they’ve constructed homes in Haiti, Mexico, and Bolivia. By next summer, the organization hopes to build an entire community of 100 homes in El Salvador.
The United Nations Foundation’s Chief Communications Officer Rajesh Mirchandani met Alexandria last month at the UN’s High-Level Political Forum on Sustainable Development. The week-long summit served as a global show-and-tell of sorts, allowing policymakers, entrepreneurs, and activists to share innovative solutions and lessons learned about how we can address global challenges and achieve the Sustainable Development Goals (SDGs).
Rajesh spoke to Alexandria about how she turned her personal passion into global action and why affordable and dignified housing will be crucial for realizing the SDG’s promise to “leave no one behind.”
New Story co-founder Alexandria Lafci. Photo by Braden Summers
Rajesh: How did you get interested in the issue of homelessness?
Alexandria: My mother grew up in foster care.
So from her and her siblings, I heard about what housing instability can do to mental and physical health and overall stability.
And then I was actually a Teach For America educator in Washington, D.C. and about a third of my students were homeless for either all or part of the year, so I directly got to see how that impacted the students and their families.
In 2014, I met my co-founders and they told me about families in Haiti. Four years after the earthquake, families were still living in the same thin tarp tents that they were given immediately after that disaster. So it really just started with wanting to build a few homes for those families that we met in Haiti. Fast forward to today and we’ve created over 6,500 homes. Now I’m trying to bring tech solutions to make the sector more effective and productive.
Rajesh: How did you come up with the idea of 3D-printing homes?
Alexandria: We built those 6,500 homes through traditional methods, but we realized we were growing incrementally.
So how can we have an exponential impact, not just for us but for this sector. There are a lot of organizations and governments that are building homes. How can we help all of them? So we asked ourselves, Can we build homes faster? Can we build them less expensively without sacrificing quality and even increasing quality?
After a lot of research and talking to people, 3D-printing just kept rising to the top. Then we met a construction technology company called ICON and we developed a 3D-home printer with them in a few months. It’s unique in that it’s meant to work specifically in the areas that we work, in places like rural Haiti where there is very rugged terrain, using locally available materials, being very easy to transport, being very easy to operate.
A tent home in Leveque, Haiti. (Photo credit: New Story/Adam Brophy)
Rajesh: What was the reason for working in countries around the world?
Alexandria: So for New Story specifically, my co-founder had gone and volunteered in Haiti.
That’s how he first became aware of that specific issue. So it made sense through the relationships that we had to work and start in Haiti.
For my experience, I went on a trip to Peru when I was 15 years old so that’s when I got passionate about international development. It’s what I studied in college and since then I’ve worked on land reform issues in Africa and microfinance in central America. So my deep passion is poverty alleviation and international development.
Rajesh: It’s quite a big deal to go from Teach for America to setting up an organization that’s actually building homes. I think a lot of people will be impressed or daunted and would think, “Oh, I couldn’t possibly do that.” So how do you tell them that you can do this too?
Alexandria: Yeah, I did not fancy myself as an entrepreneur necessarily. One fun fact is that when my two co-founders and I started New Story, we were all 24 years old. I think when people have a big idea, they think of the big idea and that can be very daunting.
If we started thinking about 3D-home printing or let’s get close to 2,000 homes built, I think we would have never started, right? You get paralyzed by how big that goal is.
But we didn’t start that way. We said, “Can we build a few homes for the families we had met in Haiti? And can we build a better donor experience?” Those are the two tenets that we started with. We felt like, Yes, we could do those two things and then it really grows from there and you increase your ambitions from there.
So I’d say think big and have a lofty goal, but then break it down into those smaller steps. And ask yourself: What can I do in the next three to six months that would let me know if this is something I want to continue building?
A community rendering of New Story’s 3D-printed homes. (Photo credit: New Story)
Rajesh: So tell us about the 3D-printed homes. How far are you taking that idea?
Alexandria: This is not a thing from science fiction, 3D-home printing is already here.
There are a number of organizations that are working with 3D structure-building. The reason why what we’re doing is significant is because those are typically for-profit motivations. We designed our printer to work for our context. It’s printing houses and early next year we’ll be printing an entire community in El Salvador. A community of 100-plus homes will be finished by the summer of 2019.
Rajesh: I want to rewind and have you listen to what you just said: “Early next year we will be printing an entire community.” What does it sound like when you hear yourself say that?
Alexandria: You know, I’m just so into the day-to-day issues like, “Let’s get land for this,” or getting into countries through customs. I think too often when we’re working on big problems or exciting things, we’re so deep in the nitty gritty that we don’t zoom out and really appreciate the magnitude of what’s happening, but it is incredibly exciting.
I won’t understate how the construction industry typically doesn’t innovate.
The nonprofit sector — unfortunately, the sector I love— typically does not innovate. And so to do something of this magnitude, I think is not only significant for housing. This is a major step. It’s a quantum leap in how housing can been built, but I really hope this is a signal to other nonprofits working on different issues on how they can just take bigger swings to try to get breakthroughs in how they look at their issue area.
Children stand in front of a tent slum in Haiti. (Photo credit: New Story/Adam Brophy)
Rajesh: You’ve created a solution from a personal passion, from one idea. And housing is included in the Sustainable Development Goals. If you help people get access to sustainable and affordable housing, you could help them make progress in so many other goals as well. How much of that drives you?
Alexandria: That is really what got me into this work. Back in 2014, my co-founder and I were talking about building houses in Haiti.
For me, because of those previous experiences with my mother as an educator, I was aware that housing has this broad-reaching impact. So that’s actually how I came into this work.
Already, we’ve seen the impact on students’ school performance and attendance. We’ve seen its impact on people’s mental and physical health, as I’m sure you can imagine. We’ve seen entrepreneurship crop up in the communities that we’re working in.
I have really started to believe that housing is a prerequisite for having a high-quality life. When we think of life’s basic needs, we tend to think of water and food. Shelter is there too. And it really is paramount in order to live a quality life.
Rajesh: So for people who might be listening to you speaking about this who are thinking “Oh, I can’t do that, I can’t do what she’s done,” what do you say to them? How do you go from taking a personal passion and turning it into an SDG solution?
Alexandria: I was 24 years old in a job that I actually hated when I started this.
And again, I think it’s important to think big, but then work on what the immediate tangible steps are. And get a good group of people around you. I do know people who’ve started organizations as one person, but that’s a very lonely place to be. And so probably my two biggest pieces of advice would be find people who are just as passionate as you— whose values are aligned with yours—to work alongside and then start small.
To learn more about the individuals and innovations that are driving global progress, listen to the latest episode of the Global Goalscast podcast.
All about 3D printing. additive manufacturing. Basic concepts.
- 1 Technology
- 2 Terminology
- 3 Fundamentals
- 4 Printing Technologies
- 5 3D printers
- 6 Application
- 7 Domestic and hobby use
- 8 Clothing
- 9 3D bioprinting
- 10 3D printing of implants and medical devices
- 11 3D printing services
- 12 Research into new applications
- 13 Intellectual Property
- 14 Influence of 3D printing
- 15 Space research
- 16 Social change
- 17 Firearms
Technology
Charles Hull - the father of modern 3D printing
3D printing is based on the concept of building an object in successive layers that display the contours of the model.
In fact, 3D printing is the complete opposite of traditional mechanical production and processing methods such as milling or cutting, where the appearance of the product is formed by removing excess material (so-called "subtractive manufacturing").
3D printers are computer-controlled machines that build parts in an additive way. Although 3D printing technology appeared in the 80s of the last century, 3D printers were widely used commercially only in the early 2010s. The first viable 3D printer was created by Charles Hull, one of the founders of 3D Systems Corporation. At the beginning of the 21st century, there was a significant increase in sales, which led to a sharp drop in the cost of devices. According to the consulting firm Wohlers Associates, the global market for 3D printers and related services reached $2.2 billion in 2012, growing by 29%.% compared to 2011.
3D printing technologies are used for prototyping and distributed manufacturing in architecture, construction, industrial design, automotive, aerospace, military-industrial, engineering and medical industries, bioengineering (to create artificial fabrics), fashion and footwear, jewelry, in education, geographic information systems, food industry and many other areas.
According to research, open source home 3D printers will allow you to win back the capital costs of your own purchase through the economy of household production of items.
Terminology
Additive manufacturing involves the construction of objects by adding the necessary material, and not by removing excess, as is the case with subtractive methods
The term "additive manufacturing" refers to the technology of creating objects by applying successive layers material. Models made using the additive method can be used at any stage of production - both for the production of prototypes (so-called rapid prototyping) and as finished products themselves (so-called rapid production).
In manufacturing, especially machining, the term "subtractive" implies more traditional methods and is a retronym coined in recent years to distinguish between traditional methods and new additive methods.
Although traditional manufacturing has used essentially "additive" methods for centuries (such as riveting, welding, and screwing), they lack a 3D information technology component. Machining, on the other hand, (the production of parts of an exact shape), as a rule, is based on subtractive methods - filing, milling, drilling and grinding.
The term "stereolithography" was defined by Charles Hull in a 1984 patent as "a system for generating three-dimensional objects by layering".
Fundamentals
3D printed models
3D models are created by hand-held computer graphic design or 3D scanning. Hand modeling, or the preparation of geometric data for the creation of 3D computer graphics, is somewhat like sculpture. 3D scanning is the automatic collection and analysis of data from a real object, namely shape, color and other characteristics, with subsequent conversion into a digital three-dimensional model.
Both manual and automatic creation of 3D printed models can be difficult for the average user. In this regard, 3D printed marketplaces have become widespread in recent years. Some of the more popular examples include Shapeways, Thingiverse, and Threeding.
3D printing
The following digital models are used as drawings for 3D printed objects , powder, paper or sheet material, building a 3D model from a series of cross sections. These layers, corresponding to virtual cross-sections in the CAD model, are connected or fused together to create an object of a given shape. The main advantage of this method is the ability to create geometric shapes of almost unlimited complexity.
"Resolution" of the printer means the thickness of the applied layers (Z-axis) and the accuracy of positioning the print head in the horizontal plane (along the X and Y axes). Resolution is measured in DPI (dots per inch) or micrometers (the obsolete term is "micron").
Typical layer thicknesses are 100µm (250 DPI), although some devices like the Objet Connex and 3D Systems ProJet are capable of printing layers as thin as 16µm (1600 DPI). The resolution on the X and Y axes is similar to that of conventional 2D laser printers. A typical particle size is about 50-100µm (510 to 250 DPI) in diameter.
One of the methods for obtaining a digital model is 3D scanning. Pictured here is a MakerBot Digitizer
3D Scanner Building a model using modern technology takes hours to days, depending on the method used and the size and complexity of the model. Industrial additive systems can typically reduce the time to a few hours, but it all depends on the type of plant, as well as the size and number of models produced at the same time.
Traditional manufacturing methods such as injection molding can be less expensive when producing large batches of polymer products, but additive manufacturing has advantages in small batch production, allowing for higher production rates and design flexibility, along with increased cost per unit produced.
In addition, desktop 3D printers allow designers and developers to create concept models and prototypes without leaving the office.
Machining
FDM Type 3D Printers
Although the resolution of the printers is adequate for most projects, printing slightly oversized objects and then subtractively machining them with high-precision tools allows you to create models of increased accuracy.
The LUMEX Avance-25 is an example of devices with a similar combined manufacturing and processing method. Some additive manufacturing methods allow for the use of multiple materials, as well as different colors, within a single production run. Many of the 3D printers use "supports" or "supports" during printing. Supports are needed to build model fragments that are not in contact with the underlying layers or the working platform. The supports themselves are not part of the given model, and upon completion of printing, they either break off (in the case of using the same material as for printing the model itself), or dissolve (usually in water or acetone - depending on the material used to create the supports).
).
Printing technologies
Since the late 1970s, several 3D printing methods have come into being. The first printers were large, expensive and very limited.
Complete skull with supports not yet removed
A wide variety of additive manufacturing methods are now available. The main differences are in the layering method and consumables used. Some methods rely on melting or softening materials to create layers: these include selective laser sintering (SLS), selective laser melting (SLM), direct metal laser sintering (DMLS), fusing deposition printing (FDM or FFF). Another trend has been the production of solid models by polymerization of liquid materials, known as stereolithography (SLA).
In the case of lamination of sheet materials (LOM), thin layers of material are cut to the required contour, and then joined into a single whole. Paper, polymers and metals can be used as LOM materials.
Each of these methods has its own advantages and disadvantages, which is why some companies offer a choice of consumables for building a model - polymer or powder. LOM printers often use regular office paper to build durable prototypes. The key points when choosing the right device are the speed of printing, the price of a 3D printer, the cost of printed prototypes, as well as the cost and range of compatible consumables.
Printers that produce full-fledged metal models are quite expensive, but it is possible to use less expensive devices for the production of molds and subsequent casting of metal parts.
The main methods of additive manufacturing are presented in the table:
| | ||
| Method | Technology | Materials used |
| Extrusion | Fused deposition modeling (FDM or FFF) | Thermoplastics (such as polylactide (PLA), acrylonitrile butadiene styrene (ABS), etc. ) |
| Wire | Manufacture of arbitrary shapes by electron beam fusing (EBFȝ) | Virtually all metal alloys |
| Powder | Direct Metal Laser Sintering (DMLS) | Virtually all metal alloys |
| Electron Beam Melting (EBM) | Titanium alloys | |
| Selective laser melting (SLM) | Titanium alloys, cobalt-chromium alloys, stainless steel, aluminum | |
| Selective heat sintering (SHS) | Powder thermoplastics | |
| Selective laser sintering (SLS) | Thermoplastics, metal powders, ceramic powders | |
| Inkjet | 3D Inkjet Printing (3DP) | Gypsum, plastics, metal powders, sand mixtures |
| Lamination | Lamination Object Manufacturing (LOM) | Paper, metal foil, plastic film |
| Polymerization | Stereolithography (SLA) | Photopolymers |
| Digital LED Projection (DLP) | Photopolymers |
Extrusion Printing
Fused Deposition Modeling (FDM/FFF) was developed by S.
Scott Trump in the late 1980s and commercialized in the 1990s by Stratasys, a company of which Trump is credited as one of the founders. Due to the expiration of the patent, there is a large community of open source 3D printer developers as well as commercial organizations using the technology. As a consequence, the cost of devices has decreased by two orders of magnitude since the invention of the technology.
3D printers range from simple do-it-yourself printers to plastic...
Fusion printing process involves the creation of layers by extrusion of a fast-curing material in the form of microdrops or thin jets. Typically, consumable material (such as thermoplastic) comes in the form of spools from which the material is fed into a printhead called an "extruder". The extruder heats the material to its melting temperature, followed by extrusion of the molten mass through a nozzle. The extruder itself is driven by stepper motors or servomotors to position the print head in three planes.
The movement of the extruder is controlled by a manufacturing software (CAM) linked to a microcontroller.
A variety of polymers are used as consumables, including acrylonitrile butadiene styrene (ABS), polycarbonate (PC), polylactide (PLA), high pressure polyethylene (HDPE), polycarbonate-ABS blends, polyphenylene sulfone (PPSU), etc. Typically, polymer supplied in the form of a filler made of pure plastic. There are several projects in the 3D printing enthusiast community that aim to recycle used plastic into materials for 3D printing. The projects are based on the production of consumables using shredders and melters.
FDM/FFF technology has certain limitations on the complexity of the generated geometric shapes. For example, the creation of suspended structures (such as stalactites) is impossible by itself, due to the lack of necessary support. This limitation is compensated by the creation of temporary support structures that are removed after printing is completed.
Powder print
Selective sintering of powder materials is one of the additive manufacturing methods. Model layers are drawn (sintered) in a thin layer of powdered material, after which the work platform is lowered and a new layer of powder is applied. The process is repeated until a complete model is obtained. The unused material remains in the working chamber and serves to support the overhanging layers without requiring the creation of special supports.
The most common methods are based on laser sintering: selective laser sintering (SLS) for working with metals and polymers (e.g. polyamide (PA), glass fiber reinforced polyamide (PA-GF), glass fiber (GF), polyetheretherketone) (PEEK), polystyrene (PS), alumide, carbon fiber reinforced polyamide (Carbonmide), elastomers) and direct metal laser sintering (DMLS).
... to expensive industrial plants working with metals
Selective Laser Sintering (SLS) was developed and patented by Carl Deckard and Joseph Beeman of the University of Texas at Austin in the mid-1080s under the auspices of the Defense Advanced Research Projects Agency (DARPA).
A similar method was patented by R. F. Householder in 1979, but has not been commercialized.
Selective laser melting (SLM) is characterized by the fact that it does not sinter, but actually melts the powder at the points of contact with a powerful laser beam, allowing you to create high-density materials that are similar in terms of mechanical characteristics to products made by traditional methods.
Electron Beam Melting (EBM) is a similar method for the additive manufacturing of metal parts (eg titanium alloys) but using electron beams instead of lasers. EBM is based on melting metal powders layer by layer in a vacuum chamber. In contrast to sintering at temperatures below melting thresholds, models made by electron beam melting are characterized by solidity with a corresponding high strength.
Finally, there is the 3D inkjet printing method. In this case, a binder is applied to thin layers of powder (gypsum or plastic) in accordance with the contours of successive layers of the digital model.
The process is repeated until the finished model is obtained. The technology provides a wide range of applications, including the creation of color models, suspended structures, the use of elastomers. The design of models can be strengthened by subsequent impregnation with wax or polymers.
Lamination
FDM 3D printers are the most popular among hobbyists and enthusiasts
Some printers use paper as a material for building models, thereby reducing the cost of printing. Such devices experienced the peak of popularity in the 1990s. The technology consists in cutting out the layers of the model from paper using a carbon dioxide laser with simultaneous lamination of the contours to form the finished product.
In 2005, Mcor Technologies Ltd developed a variant of the technology that uses plain office paper, a tungsten carbide blade instead of a laser, and selective adhesive application.
There are also device variants that laminate thin metal and plastic sheets.
Photopolymerization
3D printing allows you to create functional monolithic parts of complex geometric shapes, like this jet nozzle
Stereolithography technology was patented by Charles Hull in 1986. Photopolymerization is primarily used in stereolithography (SLA) to create solid objects from liquid materials. This method differs significantly from previous attempts, from the sculptural portraits of François Willem (1830-1905) to photopolymerization by the Matsubara method (1974).
The Digital Projection Method (DLP) uses liquid photopolymer resins that are cured by exposure to ultraviolet light emitted from digital projectors in a coated working chamber. After the material has hardened, the working platform is immersed to a depth equal to the thickness of one layer, and the liquid polymer is irradiated again. The procedure is repeated until the completion of the model building. An example of a rapid prototyping system using digital LED projectors is the EnvisionTEC Perfactory.
Inkjet printers (eg Objet PolyJet) spray thin layers (16-30µm) of photopolymer onto the build platform until a complete model is obtained. Each layer is irradiated with an ultraviolet beam until hardened. The result is a model ready for immediate use. The gel-like support material used to support the components of geometrically complex models is removed after the model has been handcrafted and washed. The technology allows the use of elastomers.
Ultra-precise detailing of models can be achieved using multiphoton polymerization. This method is reduced to drawing the contours of a three-dimensional object with a focused laser beam. Due to non-linear photoexcitation, the material solidifies only at the focusing points of the laser beam. This method makes it easy to achieve resolutions above 100 µm, as well as build complex structures with moving and interacting parts.
Another popular method is curing with LED projectors or "projection stereolithography".
Projection stereolithography
This method involves dividing a 3D digital model into horizontal layers, converting each layer into a 2D projection similar to photomasks. The 2D images are projected onto successive layers of photopolymer resin that harden according to the projected contours.
In some systems, the projectors are located at the bottom, helping to level the surface of the photopolymer material when the model moves vertically (in this case, the build platform with the applied layers moves up, rather than sinking into the material) and reduces the production cycle to minutes instead of hours.
The technology allows you to create models with layers of several materials with different curing rates.
Some commercial models, such as the Objet Connex, apply resin using small nozzles.
3D printers
Industrial plants
Industrial adoption of additive manufacturing is proceeding at a rapid pace.
For example, US-Israeli joint venture Stratasys supplies $2,000 to $500,000 additive manufacturing machines, while General Electric uses high-end machines to produce gas turbine parts.
Home appliances
LOM takes papier-mâché to the next level The development of 3D printers for home use is being pursued by a growing number of companies and enthusiasts. Most of the work is done by amateurs for their own and public needs, with help from the academic community and hackers.
The oldest and longest running project in the desktop 3D printer category is RepRap. The RepRap project aims to create free and open source (FOSH) 3D printers provided under the GNU General Public License. RepRap devices are capable of printing custom-designed plastic components that can be used to build clones of the original device. Individual RepRap devices have been successfully applied to the production of printed circuit boards and metal parts.
Due to the open access to drawings of RepRap printers, many of the projects adopt the technical solutions of analogues, thus creating a semblance of an ecosystem consisting mostly of freely modifiable devices.
The wide availability of open source designs only encourages variations. On the other hand, there is a significant variation in the level of quality and complexity of both the designs themselves and the devices manufactured on their basis. The rapid development of open source 3D printers is leading to a rise in popularity and the emergence of public and commercial portals (such as Thingiverse or Cubify) offering a variety of printable 3D designs. In addition, the development of technology contributes to the sustainable development of local economies through the possibility of using locally available materials for the production of printers.
Stereolithographic 3D printers are often used in dental prosthetics
The cost of 3D printers has been declining at a significant rate since about 2010: devices that cost $20,000 at the time are now $1,000 or less. Many companies and individual developers are already offering budget RepRap kits under $500. The Fab@Home open source project has led to the development of general purpose printers capable of printing anything that can be squeezed through a nozzle, from chocolate to silicone putty and chemicals.
Printers based on this design have been available as kits since 2012 for around $2,000. Some 3D printers, including the mUVe 3D and Lumifold, are designed to be as affordable as possible from the start, with the Peachy Printer being priced around $100. .
Professional Kickstarter funded printers often perform well: Rapide 3D printers are quiet and fumes free at $1499. 3D Doodler's '3D Printing Pen' Raised $2.3M in Kickstarter donations, with a selling price of $99 for the device itself. True, it is difficult to call the 3D Doodler a full-fledged 3D printer.
3D Systems Cube is a popular consumer 3D printer
As prices drop, 3D printers are becoming more attractive for home production. In addition, home use of 3D printing technologies can reduce the environmental footprint of industry by reducing the volume of consumables and the energy and fuel costs of transporting materials and goods.
Parallel to the creation of home 3D-printing devices, the development of devices for processing household waste into printed materials, the so-called.
Recyclebot. For example, the commercial model Filastrucer was designed to recycle plastic waste (shampoo bottles, milk containers) into inexpensive consumables for RepRap printers. Such methods of household disposal are not only practical, but also have a positive impact on the ecological situation.
The development and customization of RepRap 3D printers has created a new category of semi-professional printers for small businesses. Manufacturers such as Solidoodle, RoBo and RepRapPro offer kits for under $1,000. The accuracy of these devices is between industrial and consumer printers. Recently, high-performance printers using a delta-shaped coordinate system, or the so-called "delta robots", are gaining popularity. Some companies offer software to support printers made by other companies.
Application
The use of LED projectors helps reduce the cost of stereolithography printers. In the illustration DLP printer Nova
3D printing allows you to equalize the cost of producing one part and mass production, which poses a threat to large-scale economies.
The impact of 3D printing may be similar to the introduction of manufacture. In the 1450s, no one could predict the consequences of the printing press, in the 1750s, no one took the steam engine seriously, and transistors 19The 50s seemed like a curious innovation. But the technology continues to evolve and is likely to have an impact on every scientific and industrial branch with which it comes into contact.
The earliest application of additive manufacturing can be considered rapid prototyping, aimed at reducing the development time of new parts and devices compared to earlier subtractive methods (too slow and expensive). The improvement of additive manufacturing technologies leads to their spread in various fields of science and industry. The production of parts previously only available through machining is now possible through additive methods, and at a better price.
Applications include breadboarding, prototyping, molding, architecture, education, mapping, healthcare, retail, etc.
Industrial applications:
Rapid prototyping: Industrial 3D printers have been used for rapid prototyping and research since the early 1980s . As a rule, these are quite large installations using powder metals, sand mixtures, plastics and paper. Such devices are often used by universities and commercial companies.
Advances in rapid prototyping have led to the creation of materials suitable for the production of final products, which in turn has contributed to the development of 3D production of finished products as an alternative to traditional methods. One of the advantages of fast production is the relatively low cost of manufacturing small batches.
Rapid production: Rapid production remains a fairly new method whose possibilities have not yet been fully explored. Nevertheless, many experts tend to consider rapid production a new level of technology. Some of the most promising areas for rapid prototyping to adapt to rapid manufacturing are selective laser sintering (SLS) and direct metal sintering (DMLS).
Bulk customization: Some companies offer services for customizing objects using simplified software and then creating unique custom 3D models. One of the most popular areas was the manufacture of cell phone cases. In particular, Nokia has made publicly available the designs of its phone cases for user customization and 3D printing.
Mass production: The current low print speed of 3D printers limits their use in mass production. To combat this shortcoming, some FDM devices are equipped with multiple extruders, allowing you to print different colors, different polymers, and even create several models at the same time. In general, this approach increases productivity without requiring the use of multiple printers - a single microcontroller is enough to operate multiple printheads.
Devices with multiple extruders allow the creation of several identical objects from only one digital model, but at the same time allow the use of different materials and colors.
The print speed increases in proportion to the number of print heads. In addition, certain energy savings are achieved through the use of a common working chamber, which often requires heating. Together, these two points reduce the cost of the process.
Many printers are equipped with dual printheads, however this configuration is only used for printing single models in different colors and materials.
Consumer and hobby use
Today, consumer 3D printing mainly attracts the attention of enthusiasts and hobbyists, while practical use is rather limited. However, 3D printers have already been used to print working mechanical clocks, woodworking gears, jewelry, and more. Home 3D printing websites often offer designs for hooks, doorknobs, massage tools, and more.
3D printing is also being used in hobby veterinary medicine and zoology – in 2013, a 3D printed prosthesis allowed a duckling to stand up, and hermit crabs love stylish 3D printed shells.
3D printers are widely used for the domestic production of jewelry - necklaces, rings, handbags, etc.
The Fab@Home open project aims to develop general purpose home printers. The devices have been tested in research environments using the latest 3D printing technologies for the production of chemical compounds. The printer can print any material suitable for extrusion from a syringe in the form of a liquid or paste. The development is aimed at the possibility of home production of medicines and household chemicals in remote areas of residence.
Student project OpenReflex resulted in a design for an analog SLR camera suitable for 3D printing.
Clothing
3D printing is gaining ground in the fashion world as couturiers use printers to experiment with swimwear, shoes and dresses. Commercial applications include rapid prototyping and 3D printing of professional athletic shoes - the Vapor Laser Talon for soccer players and New Balance for track and field athletes.
3D bioprinting
EBM titanium medical implants
3D printing is currently being researched by biotech companies and academic institutions. The research is aimed at exploring the possibility of using inkjet/drip 3D printing in tissue engineering to create artificial organs. The technology is based on the application of layers of living cells on a gel substrate or sugar matrix, with a gradual layer-by-layer build-up to create three-dimensional structures, including vascular systems. The first 3D tissue printing production system based on NovoGen bioprinting technology was introduced in 2009year. A number of terms are used to describe this research area: organ printing, bioprinting, computer tissue engineering, etc.
One of the pioneers of 3D printing, research company Organovo, conducts laboratory research and develops the production of functional 3D human tissue samples for use in medical and therapeutic research.
For bioprinting, the company uses a NovoGen MMX 3D printer. Organovo believes that bioprinting will speed up the testing of new medicines before clinical trials, saving time and money invested in drug development. In the long term, Organovo hopes to adapt bioprinting technology for graft and surgical applications.
3D printing of implants and medical devices
3D printing is used to create implants and devices used in medicine. Successful surgeries include examples such as titanium pelvic and jaw implants and plastic tracheal splints. The most widespread use of 3D printing is expected in the production of hearing aids and dentistry. In March 2014, Swansea surgeons used 3D printing to reconstruct the face of a motorcyclist who was seriously injured in a road accident.
3D printing services
Some companies offer online 3D printing services available to individuals and industrial companies.
The customer is required to upload a 3D design to the site, after which the model is printed using industrial installations. The finished product is either delivered to the customer or subject to pickup.
Exploring new applications
3D printing makes it possible to create fully functional metal products, including weapons.
Future applications of 3D printing may include the creation of open source scientific equipment for use in open laboratories and other scientific applications - fossil reconstruction in paleontology, the creation of duplicates of priceless archaeological artifacts, the reconstruction of bones and body parts for forensic analysis, the reconstruction of heavily damaged evidence collected from crime scenes. The technology is also being considered for application in construction.
In 2005, academic journals began to publish materials on the possibility of using 3D printing technologies in art. In 2007, the Wall Street Journal and Time magazine included 3D design in their list of the 100 most significant achievements of the year.
The Victoria and Albert Museum at the London Design Festival in 2011 presented an exhibition by Murray Moss entitled "Industrial Revolution 2.0: how the material world materializes again", dedicated to 3D printing technologies.
In 2012, a University of Glasgow pilot project showed that 3D printing could be used to produce chemical compounds, including hitherto unknown ones. The project printed chemical storage vessels into which “chemical ink” was injected using additive machines and then reacted. The viability of the technology was proven by the production of new compounds, but a specific practical application was not pursued during the experiment. Cornell Creative Machines has confirmed the feasibility of creating food products using hydrocolloid 3D printing. Professor Leroy Cronin of the University of Glasgow has suggested using "chemical ink" to print medicines.
The use of 3D scanning technology makes it possible to create replicas of real objects without the use of casting methods, which are costly, difficult to perform and can have a destructive effect in cases of precious and fragile objects of cultural heritage.
An additional example of 3D printing technologies being developed is the use of additive manufacturing in construction. This could make it possible to accelerate the pace of construction while reducing costs. In particular, the possibility of using technology to build space colonies is being considered. For example, the Sinterhab project aims to explore the possibility of additive manufacturing of lunar bases using lunar regolith as the main building material. Instead of using binding materials, the possibility of microwave sintering of regolith into solid building blocks is being considered.
Additive manufacturing allows you to create waveguides, sleeves and bends in terahertz devices. The high geometric complexity of such products could not be achieved by traditional production methods. A commercially available professional EDEN 260V setup was used to create structures with a resolution of 100 microns. The printed structures were galvanized with gold to create a terahertz plasmonic apparatus.
China has allocated nearly $500 million. for the development of 10 national institutes for the development of 3D printing technologies. In 2013, Chinese scientists began printing living cartilage, liver and kidney tissue using specialized 3D bioprinters. Researchers at Hangzhou Dianqi University have even developed their own 3D bioprinter for this challenging task, dubbed Regenovo. One of Regenovo's developers, Xu Mingeng, said it takes less than an hour for the printer to produce a small sample of liver tissue or a four to five inch sample of ear cartilage. Xu predicts the emergence of the first full-fledged printed artificial organs within the next 10-20 years. That same year, researchers at the Belgian Hasselt University successfully printed a new jaw for an 83-year-old woman. After the implant is implanted, the patient can chew, talk and breathe normally.
In Bahrain, sandstone-like 3D printing has created unique structures to support coral growth and restore damaged reefs.
These structures have a more natural shape than previously used structures and do not have the acidity of concrete.
Intellectual property
Section of liver tissue printed by Organovo, which is working to improve 3D printing technology for the production of artificial organs
3D printing has been around for decades, and many aspects of the technology are subject to patents, copyrights, and trademark protection. However, from a legal point of view, it is not entirely clear how intellectual property protection laws will be applied in practice if 3D printers become widely used.
distribution and will be used in household production of goods for personal use, non-commercial use or for sale.
Any of the protective measures may negatively affect the distribution of designs used in 3D printing or the sale of printed products. The use of protected technologies may require the permission of the owner, which in turn will require the payment of royalties.
Patents cover certain processes, devices, and materials. The duration of patents varies from country to country.
Often, copyright extends to the expression of ideas in the form of material objects and lasts for the life of the author, plus 70 years. Thus, if someone creates a statue and obtains copyright, it will be illegal to distribute designs for printing of an identical or similar statue.
Influence of 3D printing
Additive manufacturing requires manufacturing companies to be flexible and constantly improve available technologies to stay competitive. Advocates of additive manufacturing predict that the opposition between 3D printing and globalization will escalate as home production displaces trade in goods between consumers and large manufacturers. In reality, the integration of additive technologies into commercial production serves as a complement to traditional subtractive methods, rather than a complete replacement for the latter.
Space exploration
In 2010, work began on the application of 3D printing in zero gravity and low gravity. The main goal is to create hand tools and more complex devices "as needed" instead of using valuable cargo volume and fuel to deliver finished products to orbit.
Even NASA is interested in 3D printing
At the same time, NASA is conducting joint tests with Made in Space to assess the potential of 3D printing to reduce the cost and increase the efficiency of space exploration. Nasa's additive-manufactured rocket parts were successfully tested in July 2013, with two fuel injectors performing on par with conventionally produced parts during operational tests subjecting the parts to temperatures of around 3,300°C and high pressure levels. It is noteworthy that NASA is preparing to launch a 3D printer into space: the agency is going to demonstrate the possibility of creating spare parts directly in orbit, instead of expensive transportation from the ground.
Social change
The topic of social and cultural change as a result of the introduction of commercially available additive technologies has been discussed by writers and sociologists since the 1950s. One of the most interesting assumptions was the possible blurring of boundaries between everyday life and workplaces as a result of the massive introduction of 3D printers into the home. It also points to the ease of transferring digital designs, which, in combination with local production, will help reduce the need for global transportation. Finally, copyright protection may change to reflect the ease of additive manufacturing of many products.
Firearms
In 2012, US company Defense Distributed released plans to create a "design of a functional plastic weapon that could be downloaded and played by anyone with access to a 3D printer." Defense Distributed has developed a 3D printed version of the receiver for the AR-15 rifle, capable of withstanding more than 650 shots, and a 30-round magazine for the M-16 rifle.
The AR-15 has two receivers (lower and upper), but legal registration is tied to the lower receiver, which is stamped with a serial number. Shortly after Defense Distributed created the first working drawings for the production of plastic weapons in May 2013, the US State Department requested that the instructions be removed from the company's website.
The distribution of blueprints by Defense Distributed has fueled discussion about the possible impact of 3D printing and digital processing devices on the effectiveness of gun control. However, the fight against the proliferation of digital weapon models will inevitably face the same problems as attempts to prevent the trade in pirated content.
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FDM technology. How it works.
Hello everyone, 3DTool is with you!
In this article on 3D printing, we will look at the basic principles of FDM (Fused Deposition Modeling) technology.
Let's deal with the basic mechanics of this process. Its advantages and limitations.
FDM technology
Overlay printing (FDM) is an additive manufacturing process that is realized through the extrusion of materials. In FDM, an object is built by applying molten material according to a predetermined algorithm, layer by layer. The materials used are thermoplastic polymers and are filament-shaped.
FDM is the most widely used 3D printing technology. FDM printers are on the market in a wide variety. It's basically the first technology people come across when they start working with 3D. The following will introduce the basic principles and key aspects of this printing method.
An engineer who designs a 3D model should take into account the possibilities of technology when manufacturing a part with FDM, this knowledge will help him achieve the best result.
Process FDM printing
Here is how the FDM process works:
A spool of thermoplastic filament is loaded into the printer.
Once the nozzle reaches the required temperature, the filament is fed into the extruder and into the nozzle where it is melted.
The extruder is attached to a 3-axis system that allows it to move in the X, Y and Z directions. The molten material is extruded in thin filaments and melted in layers at predetermined locations where it then cools and solidifies. Sometimes the cooling of the material is accelerated by the use of fans attached to the extruder.
The extruder requires several passes to fill the printable area. When the layer is finished, the platform moves down (or, as in some printer models, the extruder moves up), and a new layer is welded onto the already set one. This process is repeated until the entire model is printed.
FDM printer specifications
Most FDM systems allow you to adjust several parameters of the printing process. Such as nozzle temperature, platforms, print speed, layer height and cooling fan speed.
These are usually set by the printer operator and do not bother the modeler.
What is important from a modeling standpoint is to consider the size of the table and the layer height of the part itself:
The standard printable area of a desktop 3D printer is usually 200 x 200 x 200 mm, while for industrial machines it can be up to 1000 x 1000 x 1000 mm. If a desktop 3D printer is preferable (e.g. for cost reasons), the large model can be broken down into smaller pieces and then reassembled/glued together.
The typical layer height used in FDM varies from 50 to 400 microns and can be determined during the software slicing step. A lower layer height will provide a smoother detail and more accurately represent complex geometry, while a higher layer height will print the part faster and at a lower cost. The layer height of 150-200 microns is optimal in terms of the ratio of printing time and its quality.
Part deformation
Warp is one of the most common defects in the FDM printing process.
Some plastics shrink during cooling after extrusion. Since different regions cool at different rates, their dimensions can also change at different rates. Differential cooling causes an accumulation of internal stresses that pull the layer, the one from the bottom - up, deforming it, as shown in the figure below. From a technical point of view, deformation can be prevented by more careful control of the temperature of the platform and the chamber as a whole. By increasing the adhesion between the part and the platform.
The modeler can also reduce the chance of peeling and other warp-related defects:
Large flat areas (such as a rectangular box) are more prone to deformation and should be avoided if possible.
Thin protruding elements (for example, battlements, spiers) are also prone to deformation. In this case, it can be avoided by adding some support material around the edge of the thin element (for example, a 200 micron thick rectangle) to increase the contact area.
Sharp corners deform more often than rounded shapes, so smoothing the corners slightly can achieve a good result.
Different plastics are more susceptible to deformation: ABS is generally more sensitive to this factor than PLA or PETG due to its higher glass transition temperature and relatively high coefficient of thermal expansion.
Adhesion between layers
Good adhesion between layers is very important for an FDM printed part. As the molten plastic is extruded through the nozzle, it is pressed against the previous layer. High temperature and pressure remelt the surface of the previous layer and allow the new layer to bond with the old one.
The strength of the bond between different layers is always lower than the basic strength of the material.
This means that FDM parts are inherently anisotropic: their Z strength is always less than their X/Y strength. For this reason, it is important to keep the orientation of parts in mind when designing.
For example, tensile test specimens printed horizontally with ABS at 50% infill were compared with test specimens printed vertically and found to have nearly 4 times higher tensile strength in the X, Y axis compared to the Z axis ( 17.0 MPa compared to 4.4 MPa). Such a part is stretched to failure, almost 10 times more (4.8% compared to 0.5%).
Moreover, since the molten material is pressed against the previous layer, its shape is deformed to an oval. This means that parts will always have a wavy surface, even at low layer heights, and that small features, such as small holes, may need post-printing post-processing.
Supports
The support structure is essential for creating tab geometries. Because plastic cannot be applied to air, some geometries require a support structure.
Surfaces printed with supports are usually of lower quality than the rest of the part.
For this reason, it is recommended that the part be modeled in such a way as to minimize the need for support.
Supports are usually printed from the same material as the part. There are also special materials that dissolve in a liquid, but they are mostly used in high-end desktop or industrial 3D printers. Printing on soluble supports greatly improves the surface quality of the part, but increases the overall cost of printing because a special printer with two print heads is required and because the cost of soluble material is relatively high.
Filling and shell thickness
FDM parts are usually not printed full in order to reduce printing time and save material. Instead, the outer perimeter is made with several passes, it is called a shell, and the inner part is filled with a low density structure called infill.
The filling and thickness of the body greatly affect the strength of the part. For desktop FDM printers, 25% infill density and 1mm body thickness are mostly suitable.
Usually, these are the standard settings for fast printing and a good compromise between strength and speed.
Above you see the internal geometry of parts with different degrees of filling
FDM Essential Consumables
One of the strengths of FDM printing is the wide range of materials available. They can range from conventional plastics (such as PLA and ABS) to engineering plastics (such as TPU and PETG) and high strength materials (such as PEEK).
Below is a pyramid of materials most available in FDM printing.
The material used directly affects the mechanical properties and accuracy of printing, as well as its price. The most common FDM printing materials are listed below. We will also consider the pros and cons of certain plastics. An overview of the main differences between PLA and ABS, and a detailed comparison of all common types of filament is a very extensive topic and can be found in special articles on the Internet and on thematic forums.
ABS
pros
· Durability
Good temperature resistance
Minuses
Shrinks when printed
PLA
pros
Excellent visual quality
Easy to print
· Unharmful. May come into contact with food
Minuses
· Low impact strength
· Longevity
Nylon
pros
· Very high strength
Excellent wear and chemical resistance
Minuses
· Actively absorbs water
PET-G
pros
· Unharmful. May come into contact with food
Sufficiently strong
Minuses
Capable of precise temperature print settings
TPU
pros
· Very flexible
Minuses
Printing accuracy is very difficult to achieve
PE EK
pros
· Extremely durable and lightweight
Excellent flame retardant and chemical resistance
Minus
· High price
Need a specialized 3D printer whose extruder is capable of reaching temperatures above 300C
Postprocessing
FDM parts can be processed to high standards.
When using various methods such as: sanding, polishing, priming, painting, cold welding, acetone bath (to smooth the surface and create a glossy surface), epoxy coating and plating.
Advantages and disadvantages of FDM printing
+
· FDM printing is the most economical way to produce custom thermoplastic parts and prototypes.
· FDM printing lead time is acceptable. The technology is quite affordable these days.
Wide range of materials suitable for both prototyping and some non-commercial functional applications.
-
FDM printing has the lowest dimensional accuracy and resolution compared to other 3D printing technologies, so it is not suitable for models with complex geometry and fine details
The final product will have visible layer lines, so post-processing is required for a better look
Layer adhesion mechanism makes FDM printed parts anisotropic
Highlights
· With FDM printing, prototypes and functional parts can be produced quickly and at a low cost.
